[disasm] Make jump target printing perf friendly

Makes disassembly jump target printing look more like the output of
objdump, for compatibility with perf's jump arrows. This includes
swapping the order of address and offset, and making the offset and line
numbers hex.

As a drive-by, print comment lines in objdump-v8 so that they can be
shown/hidden as "source" lines by perf.

Review-Url: https://codereview.chromium.org/2757263002
Cr-Commit-Position: refs/heads/master@{#43940}

src/disassembler.cc

@@ -41,7 +41,7 @@ const char* V8NameConverter::NameOfAddress(byte* pc) const {
       code_ == NULL ? NULL : code_->GetIsolate()->builtins()->Lookup(pc);
 
   if (name != NULL) {
-    SNPrintF(v8_buffer_, "%s  (%p)", name, static_cast<void*>(pc));
+    SNPrintF(v8_buffer_, "%p  (%s)", static_cast<void*>(pc), name);
     return v8_buffer_.start();
   }
 
@@ -49,7 +49,7 @@ const char* V8NameConverter::NameOfAddress(byte* pc) const {
     int offs = static_cast<int>(pc - code_->instruction_start());
     // print as code offset, if it seems reasonable
     if (0 <= offs && offs < code_->instruction_size()) {
-      SNPrintF(v8_buffer_, "%d  (%p)", offs, static_cast<void*>(pc));
+      SNPrintF(v8_buffer_, "%p  <+0x%x>", static_cast<void*>(pc), offs);
       return v8_buffer_.start();
     }
   }
@@ -151,7 +151,7 @@ static int DecodeIt(Isolate* isolate, std::ostream* os,
     }
 
     // Instruction address and instruction offset.
-    out.AddFormatted("%p  %4" V8PRIdPTRDIFF "  ", static_cast<void*>(prev_pc),
+    out.AddFormatted("%p  %4" V8PRIxPTRDIFF "  ", static_cast<void*>(prev_pc),
                      prev_pc - begin);
 
     // Instruction.

tools/objdump-v8

@@ -73,8 +73,11 @@ def main():
             sys.stdout.write(format_line(line))
           elif printing:
             break
-        elif printing and not is_comment(line):
-          break
+        elif printing:
+          if not is_comment(line):
+            break
+          else:
+            sys.stdout.write(line)
   else:
     sys.argv[0] = "objdump"
     sys.exit(subprocess.call(sys.argv))